Loyalty is a relative term.
The one who gives you the template for your own philosophy—the person who rocks you to your core and sets your life on its course—demands a kind of devotion that's impossible to trump. They are a standard to compare everything to, and it's rare that anything will ever quite match up.
If you're forced to choose between that template and something else—no matter how important that something is, the original will always win out. Loyalty to the person who guides your life, for good or ill, directs your actions more than anything else.
Hatake Kakashi can relate.
Heavily engaged, the Konoha shinobi have lost a good portion of their forces in subduing the cannibal Zetsu. Now that the fight seems to be under control, Kakashi allows himself to take note of the other Akatsuki member, the one with the nearly muted chakra. The eye Obito gave him pulses strangely in its socket, the active Sharingan analyzing this orange-masked unknown who seems more of a lackey than an individual agent. The lackey hangs back, radiating fear and uncertainty, until Kakashi gets a few feet closer to him.
Kakashi's Sharingan swivels and his body follows suit, responding to the sudden threat of Zetsu, injured and wrathful, bearing down on him. He is hissing, spitting venom, and lightning springs to Kakashi's hand without a second's pause. Raikiri shrieks with the cries of a thousand birds and spears into Zetsu's neck, making hissing noises as it severs bone and cartilage and sinew and comes out the other side. Zetsu's eyes roll back—the fly-trap wilts alarmingly fast—and it's over. One more Akatsuki down. A win for Konoha.
Chakra dwindling, and body really fucking battered, Kakashi turns his still-sparking hand and blood-red mismatched glare on the lackey—Tobi, who stares at him openly. Openly being a generous statement, given the mask and all. Tobi has gone still, and Kakashi looks into that eye-hole, his Sharingan very suddenly gripped—can't look away, can't move ….
The sky is melting and swirling. The ground disintegrates. Reality shudders and spirals, screaming, into the mask, the black hole, ultimate gravity.
Kakashi barely registers the thought Genjutsu! before he is sucked in too.
A moment (an eon?) later, Kakashi wakes in a world of white-on-white. The feel in the air is like Itachi's tsukiyomi, but the air around him is less forbidding. The thick white mist is cool on his face. It leaves cool trails of faint condensation on his skin. A hazy pale Sun hovers overhead and dead trees rise out of what appears to be an inch of glassy water.
Kakashi barely feels the tickle of chakra on the edge of his consciousness before Tobi speaks.
"You seem to be using my gift well, Kakashi…"
Kakashi's world reels, shudders, and implodes. What!? He whirls around, eyes wide, intensely focused and dazed at the same time. "What the hell—" he snarls.
"The eye, you dope. Looks like you mastered it. Congratulations." That voice—that inflection…
Rocks are tumbling down and they're running but it isn't fast enough and he's hurt and he's done for—then he's lifted, shoved out of harm's way but the rocks keep coming and there's a sickening crunch and the sharp scent of blood—he awakens alright and relieved, then he turns and he sees—crushed and broken, bleeding, dying…
The same voice speaks to him now—older, yes, and without the death-rattle, but the same. The same. Kakashi's stomach churns unpleasantly. "Impossible…"
"Possible," Tobi counters, raising his mechanical right arm towards his mask. An involuntary sound is wrenched from Kakashi's throat, low and wounded. This isn't happening. This can't happen…
He nearly loses it when Tobi's hand slows and falters.
" No," he barks harshly, voice ragged. "I need to see it. Show me. "
Tobi's right hand creaks softly as it reaches up to take hold of the mask. Kakashi's eyes, black and red, trace the motions with an obsessive hunger as the orange spiral is lifted up and away. His knees fail to support him when he finally sees what he's been demanding.
In front of him stands a man of about thirty, coal black Uchiha hair cut short on his head, with the pale complexion the old family so prided itself on. His left eye is shut in a weak parody of a wink; though from where he stands Kakashi can see that there is nothing but hollow space beneath the lid. The left side of his face is otherwise flawless, all alabaster skin and high, aristocratic cheekbones and sculpted jaw line.
The right side is a mess. Pitted scars lash the skin into a latticework of ruined flesh. Bones that appear to have been crushed once lend a stark irregularity to his face. The right corner of his thin-lipped mouth droops a little from nerve damage.
The final proof, of course, is the eye. A single mature Sharingan stares back at Kakashi grimly from an uneven eye socket, daring him to draw his own conclusions. The three-pronged shuriken pattern is identical to Kakashi's Mangekyou in every way, except that it's within its rightful owner.
"It's you," Kakashi whispers then, suddenly weak, suddenly boneless. "It is you…" Obito…
The man sighs heavily, looking into Kakashi's eyes—mind—soul, and simply says, "Yeah," before vanishing into the mist.
Kakashi, mind reeling, finds himself smiling incongruously. Quiet at first, then with growing hysteria he laughs, anguished tears finally spilling, streaming down his face. The air around him bends and swirls, and he is thrust back into the immediate and the real.
As the fog of Tobi's illusion clears and he finds himself supported under either arm by Sakura and Yamato, the last of the fighting dying down around them. Frantically, he scans the horizon for red clouds on a black sky, but Tobi is nowhere to be found. He panics until he catches an alien scent on the wind—familiar but different, changed by the insurmountable expanse of sixteen long years.
He knows he has to follow.
Kakashi isn't sure when—or if—the genjutsu wears off. He's discharged from the hospital as usual after a full week of recovery. The moment he leaves the building, he is sprinting for the border, and into the woods beyond. He might have been following Tobi willingly for weeks, stalking him across the countryside. Trusting his nose to work when his eyes fail him, he tails the Akatsuki man silently and stealthily. Forgetting everything else, he continues to run, losing the light finally, then, undeterred, flitting through the twilit forest like a sliver shadow.
He hunts Tobi like a wolf stalking dangerous prey. He doesn't know why Tobi is staying separate from Akatsuki for so long, but he flatters himself to think he's got something to do with it. He laughs to himself again—delirious, no doubt, from dehydration and limited food—and he feels twelve again, like he's back before everything fell apart. Dad's still dead, yeah, but he's not the key to everything, not really.
It's in a small clearing in the woods that Kakashi ultimately finds Tobi. He's sitting slumped at the base of a massive old oak tree, snoring softly. ANBU training rears its ugly head as Kakashi first and foremost considers how easy it would be to kill Tobi—one more Akatsuki member down… all the more power to his side. A kunai is in his hand before he even finishes processing the thought. He approaches silently and swiftly, poised and ready to slit Tobi's throat, barely managing to stifle the howling refusal building up within. He slashes downward.
His arm is halted abruptly by powerful fingers, and his gaze is captured flawlessly by a familiar spinning red eye, suddenly awake, in the depths of the mask.
"Going to kill me, Kakashi?" Tobi murmurs cynically.
"You're Akatsuki… I have to." Kakashi replies hollowly, hypnotized, staring into a Sharingan identical to his own, but thrumming with the power granted to it with pure Uchiha blood. He feels his body go numb. The kunai slips from nerveless fingers. The strength is gone from Kakashi's voice. "I have to," he repeats, a lump rising in his throat. "Why are you with them? Why didn't you come home?"
Kakashi perceives the ironic smile through Tobi's voice alone. "I don't remember Konoha," he sighs. "I know you, and I remember you somehow—I know we were on a mission in Grass country. I know a girl was there, and a man with golden hair. Then all I remember is agony. I was pinned, and I gave you my eye so you could keep fighting. I was buried and I was alone. I thought I died.
"I woke up in an operating room. I couldn't speak, but Orochimaru-sama and Sasori-sama were working on me. Orochimaru-sama said something about my Sharingan, about me being a damaged gift, but a gift nevertheless. They remade me. I stayed with them until Orochimaru found a more suitable target in Itachi-san, and Sasori left for Suna. Zetsu-san, the one who found me in the first place, took me on as his apprentice. Then, when Sasori-san was killed, I joined Akatsuki. I fight with them because they're all I know." He removes his mask again, placing it carefully aside. Frozen and captured in his gaze, Kakashi can only stiffen as Tobi traces the vertical scar across his borrowed eye with a single finger. His crooked smile fully visible now, he says, "The only thing I really remember about Konoha is you."
Kakashi can nearly hear his resolve splintering, like old timbers under too heavy a load. It might be the Sharingan's power, and it might be his own weakness, but either way the tears come again. He collapses on top of Tobi, suffocating on raw sobs. He feels thirteen again, like he has another chance to make things right. Tobi is tense for a second, but then his hands come up on both sides of Kakashi's face, and they gently tug his mask down.
Kakashi feels cool night air on his exposed skin, then Tobi pulls his head down and seals their lips together in a possessive kiss. Kakashi struggles for a moment, but relents almost immediately—why fight? Why bother? He reaches up as well, tangling a hand in Tobi's midnight hair and cupping the man's uneven jaw with suddenly surer fingers. He exhales through his nose, body quickening again, and kisses Tobi back with force. They rock together like this, nearly silent under the stars, each growing steadily harder, rubbing needily against one another.
Their tongues tangle and they're pressed together almost seamlessly. Tobi, with his stronger frame, grabs Kakashi and switches their positions abruptly, so that Kakashi is now lying back against the tree while Tobi weighs him down from above. They continue on in desperation; Kakashi sighing as Tobi's hand slips into his pants. He bucks up sharply as cool fingers close around his cock. Tobi moans hungrily and Kakashi spreads his legs a little wider, giving in, letting him in.
Kakashi returns to Konoha the next day alone. He goes about the day as usual, running drills with Naruto, Sakura, and Sai, spending several hours at the memorial (this time, he only talks to Yondaime), chatting idly with Iruka, then hitting the bar for drinks with Gai, Kurenai, and the other Jounin.
That night, he burns his apartment complex to the ground.
On the door of a tea shop across the street, he leaves a short note wedged into the wood, held in place with a kunai. "Another one for the Bingo Book, Godaime-sama," it reads, "I'm with Akatsuki now." His name and rank is written neatly at the bottom.
He leaves town framed in fiery light, the screams of people burning alive echoing in his wake. Behind him, he notes with a grim smile, a distinct set of twin chakras flare to life and begin to follow him.
Even in the gloom of the midnight forest, Kakashi can see the betrayal bloom in Naruto's eyes as he shakes off the boy's grip on his shoulder. "I'm going." he hears himself saying, his own voice bored and cold, "If you follow me, I'll kill you. Don't try to follow me."
Naruto stares at him, ashen-faced, fists clenched at his sides, mouth drawn into a tense line. "So you're really with them now?" He whispers, sounding too old, too hurt, too harsh.
"Aa." A curt reply, a pang of almost-regret, and Kakashi flickers away into the night.
Naruto lets him go.
Konoha has taken his defection well, Kakashi hears from a chatty fisherman who lacked the skill to see through his henge. "Sharingan Kakashi" is now being hunted down by a platoon of Konoha's elite ninja, and there's a hefty price for his head. Rumour has it he's running with Akatsuki now, and should be considered deadly and dangerous. Kakashi speculates on his own whereabouts with the man genially, then drives a kunai into his throat before he can blink again.
Tobi is waiting for him in the glade again, masked face as inscrutable as ever. His voice, of course, belies his excitement.
"You really did it," he breathes, sounding impressed.
Kakashi finds he doesn't want to talk about it just yet. His jaw twitches underneath the fabric of his mask and he merely nods, falling into step with the man who's become the scope and breadth of his entire world. Not for the first time, Kakashi wonders if he's lost his mind, but he answers himself just as quickly. Everything he's done since his first mission as a Jounin has been defined by Obito, modeled after Obito, aimed at the golden-freaking-standard of the noble martyr Obito.
But Tobi-Obito is here now, impossibly alive, and Kakashi would be lying to himself if he thought he could be anywhere else.
Kakashi shows up thirty-four minutes and twenty-seven seconds late to his first meeting with Akatsuki.
Akatsuki doesn't take kindly to Tobi's plan at first, as it turns out he never asked them about Kakashi joining. Itachi is the first one to acknowledge that having another Mankekyou Sharingan would only strengthen Akatsuki, though he says this with a substantial glare leveled at Kakashi. Deidara is bitter about it at first ("That dickhead took my arm, mmm!"), but the Leader silences him. Kakashi's intimate knowledge of the Kyuubi's Jinchuuriki makes him invaluable to the organization. He can direct them to Naruto when the time to collect the 9th bijuu comes. That, combined with his knowledge of over a thousand jutsu, tips the scales in his favour and he's presented with his black cloak and Zetsu's old ring that same night.
As he learns of the true nature of Akatsuki's plans, Kakashi can only think that Konoha has no idea what's coming to them.
Kakashi has a good laugh at Itachi's expense when they get their hands on an updated Bingo Book. Apparently, he's been ranked as more dangerous than the clan-slaughtering Uchiha heir. Itachi pretends to be above such petty concerns, barely sparing the little book a glance, but Kakashi is an expert at reading body language. The minute tension in the shoulders tells him that the little weasel is jealous, and he takes a perverse delight in rubbing it in ever-so-slightly.
He knows the whole thing's fucked up, but he's alright with that.
"Tobi…" Kakashi begins one evening, lying in bed, shifting somewhat uncomfortably in his red-on-black robes. "Why aren't you angry that I killed the man who rescued you?"
One Sharingan eye narrows into a slight frown before a grin relaxes the battered face. The gloved hand strokes his lip with a thumb. Kakashi shivers. "When the mask's off," Tobi murmurs, "call me Obito. Besides, you're a much better lay. Don't worry about it."
Kakashi's smile is slow, creeping across his mouth like ice melting. "Okay, okay."
Tobi—no, Obito, smirks like a demented Cheshire cat before pouncing on him. "Kakashi is a good boy," he says in a sing-song voice, peeling Kakashi out of his robes.
Kakashi laughs now, honest and bitter at the same time. "Hardly."
Uchiha Obito can be childish at times. Kakashi supposes it's because he's never had to grow up. That, or the extensive brain damage. He has fits sometimes if he doesn't get his way, or if he is startled, or especially if he's misplaced his all-important mask. He will throw things and get into tantrum-like rages, bellowing himself hoarse and demolishing his surroundings. If someone's kill tally exceeds his, he will sulk. If someone outclasses him in a fight, he'll pout. Kakashi is guilty of these last two often enough, but Obito gets revenge on him in other ways. He sends his chakra crawling across the bare skin at the nape of Kakashi's neck like little spiders, making the battle-hardened Copy Ninja shudder deliciously at the most inopportune times.
The faint blush on Kakashi's pale face when he reports to the Leader isn't nerves, and it isn't discomfort. ANBU captains can keep their masks on, even when their faces are bare. Hatake Kakashi, however, was never too good at hiding desperate want.
Deidara notices this and finds it hilarious, mmm.
The sound Obito makes when he comes reminds Kakashi of a ninja he'd seen once. The man was brought back from a mission with severe head trauma. He was comatose for weeks, and at night the hospital halls would echo with loud, warbling, strangled cries. When Kakashi asked her about it with a horrified sort of fascination, Tsunade explained in that blunt, practical way of hers that the noises were part of a recovery process. The neurons in the man's brain were firing at random, casting out blindly to regain the connections they'd lost.
Obito rams into him sharply, branding Kakashi's insides with liquid fire, and groaning wildly with the sensation of it all. Kakashi reckons, quickly fucking himself to orgasm on Obito's softening cock, that he may just have found his missing synapse.
On another silent night, Kakashi is lazing between sleep and wakefulness, sprawled naked across Obito's legs and chest like an oversized lapdog. As he inhales, his chest expands and presses against Obito's and as he exhales, Obito's chest rises to meet his. He revels in the connectedness, happy to drift along where sensation alone is enough. He feels mechanical fingers toy absently with his wild silver hair.
"You know," Obito muses, breaking the silence, "I don't think this is the way things were supposed to go at all…"
Kakashi merely grunts his agreement.
It isn't, but you have to take what you can get.
When Naruto finally kills him, it's like a relief. That lingering twinge of guilt on his conscience vanishes as a Rasengan, sharpened to a million needles of pain with perfect Wind chakra technique, tears its way through his abdomen. Lessons well learned indeed. He doesn't try to dodge. Obito has fallen—Sasuke's Chidori has run him through. Sasuke—oh good, they got him back—looks lost and wild. Brother dead, cousin dying—he's the true reason for his clan's extinction in the end. Sakura watches in horror as Kakashi's body stiffens in swift, acute agony. Gasping through demolished lungs now, he looks into Naruto's eyes with something akin to acknowledgement. His most neglected student has indeed become a master. Somewhere in those sad blue eyes, echoes of Yondaime and the man that Obito could have been stare back. Kakashi collapses into the dirt.
Naruto's anguished cries fade into the background noise. Two eyes meet across the expanse of rubble, twin whorls of deepest red that have seen so much, both together and apart. For the second time, Obito fades with a smile on his face, and Kakashi prepares to follow him, finally.
The sun rises, hot and fierce and blinding, scorching the horizon and filling his eyes with light and colour.
Drowning in blood now, going cold all over, Kakashi is content to believe that, for the first time, he's actually gotten it right.